In the field of mobile communication, miniaturization continues with increasingly higher integration. For example, in future telephones, in addition to 4 Global System for Mobile Communications (GSM) bands, there will be an additional 3 bands for Wideband Code Division Multiple Access (WCDMA), for which mobile telephones have to be designed. In addition, different transmission standards, such as, WCDMA and GSM, require different architectures both with regard to the front end and with regard to the corresponding RF integrated circuit (IC).
WCDMA uses frequency duplex methods (FDD), and it requires a duplexer at the antenna to be able to transmit and receive simultaneously. In the case of GSM, one transmission-receiver toggle switch is sufficient, which can also be used as a band toggle switch.
FIG. 1 shows the classic architecture of a known multimode-multiband front end for QB (quadband) GSM/EDGE and 3-band WCDMA. All components are placed as discrete elements on the circuit board of the mobile telephone and are connected to an antenna via a coupling element M. This coupling element in the simplest case is a 1-on-N switch. As is already apparent from FIG. 1, in this type of architecture, only receive (RX) and transmit (TX) paths for GSM can be reasonably arranged, and connected by the shortest path. However, as soon as paths for WCDMA are added, a decision must be made regarding the side on which the duplexer component should be arranged.
In FIG. 1, the duplexer is arranged, for example, on the TX side, which has the consequence that feed lines from the RX gate of the duplexer into the WCDMA receiver (RF IC) cross other signal paths and/or become too long, which results either in undesired signal coupling or increased insertion loss.
The problem of the invention is to provide a module that can be used in a multiband-multimode front end, and that allows a more elegant, more cost advantageous and/or more compact connection in the front end.